Develop Reference

send data from socket to c# in android

I am trying to develop an application in android to sent the gps data to my pc .the android part is :
#Override
public void onLocationChanged(Location location) {
// TODO Auto-generated method stub
float latitude = (float) (location.getLatitude());
float longitude = (float) (location.getLongitude());
showMessage("Student Details", "Latitude: " + latitude + ", Longitude: " + longitude);
Log.i("Geo_Location", "Latitude: " + latitude + ", Longitude: " + longitude);
try {
Socket socket = new Socket("192.168.1.5",5000);
DataOutputStream DOS = new DataOutputStream(socket.getOutputStream());
DOS.writeUTF("HELLO_WORLD");
socket.close();
} catch (UnknownHostException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
And the c# code or server code is :
public AsyncCallback pfnWorkerCallBack;
private Socket m_mainSocket;
private Socket[] m_workerSocket = new Socket[25];
private int m_clientCount = 0;
private string ipaddress;
public Form1()
{
InitializeComponent();
}
private void Form1_Load(object sender, EventArgs e)
{
startfun();
}
public void startfun()
{
try
{
// DrawMapPersian();
ipaddress = "192.168.1.5";
// Check the port value
string portStr = "5000";
int port = System.Convert.ToInt32(portStr);
// Create the listening socket...
m_mainSocket = new Socket(AddressFamily.InterNetwork,
SocketType.Stream,
ProtocolType.Tcp);
IPEndPoint ipLocal = new IPEndPoint(IPAddress.Any, port);
// Bind to local IP Address...
m_mainSocket.Bind(ipLocal);
listBox1.Items.Add("Server Started...");
// Start listening...
m_mainSocket.Listen(20);
listBox1.Items.Add("Server Listening for ...");
// Create the call back for any client connections...
m_mainSocket.BeginAccept(new AsyncCallback(OnClientConnect), null);
}
catch (Exception qqq)
{
using (StreamWriter writer =
new StreamWriter(#"e:\a.txt"))
{
writer.Write(qqq.Message);
}
}
}
public void OnDataReceived(IAsyncResult asyn)
{
try
{
SocketPacket socketData = (SocketPacket)asyn.AsyncState;
int iRx = 0;
// Complete the BeginReceive() asynchronous call by EndReceive() method
// which will return the number of characters written to the stream
// by the client
iRx = socketData.m_currentSocket.EndReceive(asyn);
string res = GetParameters(socketData.dataBuffer);
Console.WriteLine(res.ToString());
}
another thing that i should say i add this permissions to manifest <uses-permission android:name="android.permission.ACCESS_WIFI_STATE" /> <uses-permission android:name="android.permission.INTERNET" />
I connected the mobile phone to the wireless network ,i mean the mobile can access my ip .
The problem is the gps data is generated so slowly i don't know why ?another problem is the android application doesn't send any data to server ,

Client
To accelerate the location update, you have to specify to the Activity the location update interval when setting the LocationListener implementation.
Something like :
LocationListener impl = new MyLocationListenerImpl();
long interval = 4000;//change your code here
setLocationListener(impl, interval);
(Note that the code above is more like a pseudo code, since It's been a long time since I have touched LocationListener).
Server
The code you provided does not mention the "OnDataReceived" member function. So I think that you should dig in this way.
Unless sockets are used on purpose, consider using Http Protocol and frameworks like ASP.NET and loopj Async Http to pass data to a server, it's easier !

TCP Socket BeginReceive stops after receiving few messages

This is my scenario:
Client :
Send xml data in pieces continuously 24/7 - (It is working fine and it is not in my control).
Server - My Code:
1. Listen continuously.
2. Receive the incoming message, buffer it and create valid xml from buffer.
3. Send it to the MSMQ ( Host will do this )
I wrote a tcp server code (adding pieces of code from google), which will be hosted in windows service. Everything works fine when I run the service in local but when I place it PROD, it listens upto 73K messages and it stops receiving. It is not throwing any exception. It just blocks at BeginReceive function. I have tried using ReceiveTimeOut also. I have seen netstat also and the connections is still in established stat.
When I restart the service, it again works fine. Here I am posting my server code. Please help on this.
StringBuilder content = new StringBuilder();
public event MessageReceiveEventHandler MessageReceived;
// An ArrayList is used to keep track of worker sockets that are designed
// to communicate with each connected client. Make it a synchronized ArrayList
// For thread safety
private System.Collections.ArrayList workerSocketList =
ArrayList.Synchronized(new System.Collections.ArrayList());
private int m_clientCount = 0;
private Socket m_mainSocket = null;
private AsyncCallback ReadCallback;
private AsyncCallback ConnectionCallback;
public MedDeviceListener(string ipAddress, int port, int maxConnections=100)
{
ProfileProvider.Instance.LogInformationIf(_debug);
this._port = port;
this._ipAddress = ipAddress;
this._maxConnections = maxConnections;
ReadCallback = new AsyncCallback(Receive_handler);
ConnectionCallback = new AsyncCallback(Connection_handler);
lenghtofStartMsg = header.Length;
lengthOfEndMsg = footer.Length;
}
public void Start()
{
ProfileProvider.Instance.LogInformationIf(_debug);
// Data buffer for incoming data.
byte[] bytes = new Byte[_bufferSize];
// Establish the local endpoint for the socket.
IPEndPoint localEndPoint = new IPEndPoint(IPAddress.Parse(_ipAddress), _port);
// Create a TCP/IP socket.
m_mainSocket = new Socket(AddressFamily.InterNetwork,
SocketType.Stream, ProtocolType.Tcp);
// Bind the socket to the local endpoint and listen for incoming connections.
try
{
m_mainSocket.Bind(localEndPoint);
m_mainSocket.Listen(100);
InstrumentationProvider.Instance.LogInformation("MedDeviceListener successfully connected to IP:" + _ipAddress+"\nPort :"+_port);
m_mainSocket.BeginAccept(ConnectionCallback, m_mainSocket);
}
catch (Exception e)
{
InstrumentationProvider.Instance.LogException("MedDeviceListener.Start", e);
throw e;
}
}
private void Connection_handler(IAsyncResult ar)
{
try
{
ProfileProvider.Instance.LogInformationIf(_debug);
Socket listener = (Socket)ar.AsyncState;
Socket workerSocket = listener.EndAccept(ar);
// Now increment the client count for this client
// in a thread safe manner
Interlocked.Increment(ref m_clientCount);
// Add the workerSocket reference to our ArrayList
workerSocketList.Add(workerSocket);
SendConnectedAck(_clientConnectAckMessage, m_clientCount);
WaitForData(workerSocket, m_clientCount);
//Resume the listening callback loop
listener.BeginAccept(Connection_handler, listener);
}
catch (ObjectDisposedException)
{
InstrumentationProvider.Instance.LogInformation("The listener socket has been closed");
}
catch (Exception ex)
{
InstrumentationProvider.Instance.LogException("Connection_handler", ex);
throw;
}
}
private void Receive_handler(IAsyncResult ar)
{
ProfileProvider.Instance.LogInformationIf(_debug);
StateObject state = (StateObject)ar.AsyncState;
try
{
// Retrieve the state object and the handler socket
// from the asynchronous state object.
Socket workSocket = state.workSocket;
// Read data from the client socket.
int bytesRead = workSocket.EndReceive(ar);
if (bytesRead > 0)
{
//InstrumentationProvider.Instance.LogInformationIf(_debug, bytesRead+" read..");
// There might be more data, so parse the data received so far.
string data= Encoding.ASCII.GetString(state.buffer, 0, bytesRead);
try
{
ParseIncomingMessage(data, workSocket);
}
catch(Exception parseEx)
{
content.Clear();
InstrumentationProvider.Instance.LogException("ParseIncomingMessage", parseEx);
}
}
WaitForData(state.workSocket, state.clientNumber);
}
catch (ObjectDisposedException)
{
InstrumentationProvider.Instance.LogInformation("Receive_handler: The listener socket has been closed");
}
catch (SocketException se)
{
//close the existing connection
CloseSockets();
//restart it again
this.Start();
}
}
private void WaitForData(Socket workerSocket, int clientNumber)
{
ProfileProvider.Instance.LogInformationIf(_debug);
try
{
StateObject theSocPkt = new StateObject(workerSocket, clientNumber);
workerSocket.ReceiveTimeout = 2000;
workerSocket.BeginReceive(theSocPkt.buffer, 0,
theSocPkt.buffer.Length,
SocketFlags.None,
Receive_handler,
theSocPkt);
}
catch(TimeoutException ex)
{
InstrumentationProvider.Instance.LogException("WaitForData - TimeOutException", ex);
}
catch (SocketException se)
{
InstrumentationProvider.Instance.LogException("MedDeviceListener.WaitForData", se);
//close the existing connection
CloseSockets();
//restart it again
this.Start();
}
catch (Exception ex)
{
InstrumentationProvider.Instance.LogException("WaitForData",ex);
//close the existing connection
CloseSockets();
//restart it again
this.Start();
}
}
private void ParseIncomingMessage(string msg,Socket wrkSocket)
{
Socket workSocket = wrkSocket;
bool hasStartTag = isMsgContainsStartTag(msg);
bool hasEndTag = isMsgContainsEndTag(msg);
int startTagIndex = indexOfStartTag(msg);
int endTagIndex = indexOfEndTag(msg);
// If the incomming message dont have either start or end tag
if (hasStartTag == false && hasEndTag == false)
{
content.Append(msg);
}
//check for the starttag first
//if message contains startTag
else if (hasStartTag)
{
if (startTagIndex != 0)//there is something before starttag
{
string subStr = msg.Substring(0, startTagIndex);
content.Append(subStr);
//Check and send the content
CheckSendMessage(workSocket);
//Parse the remaining message from start tag to end of the message
ParseIncomingMessage(msg.Substring(startTagIndex, msg.Length - subStr.Length), wrkSocket);
}
else if (startTagIndex == 0)
{
content.Clear();
if (hasEndTag)
{
int endOfEndTag = endTagIndex + lengthOfEndMsg;
string subStr = msg.Substring(0, endOfEndTag); //message statrs with start tag and ends contains full end tag so first get that string and send that.
content.Append(subStr);
CheckSendMessage(workSocket);
//Parse the remaining message from endtag+1 to end
ParseIncomingMessage(msg.Substring(endOfEndTag, msg.Length - endOfEndTag), wrkSocket);
}
else
{
content.Append(msg);
}
}
}
//if message contains EndTag ALONE
else if (hasEndTag)
{
int endOfEndTag = endTagIndex + lengthOfEndMsg;
string subStr = msg.Substring(0, endOfEndTag);
content.Append(subStr);
CheckSendMessage(workSocket);
//Parse remaining message after end tag
ParseIncomingMessage(msg.Substring(endOfEndTag, msg.Length - endOfEndTag), wrkSocket);
}
}
private void CheckSendMessage(Socket workSocket)
{
string msg=content.ToString().Trim();
//if content contains both start and end tag then send the content
if (isMsgContainsStartTag(msg) && isMsgContainsEndTag(msg) &&
indexOfStartTag(msg) == 0 && indexOfEndTag(msg) + lengthOfEndMsg == msg.Length)
{
//Send the message
using (MedDeviceListenerEventArgs e = new MedDeviceListenerEventArgs(msg))
{
OnReceiveComplete(e);
SendReceiveAck(workSocket, _receiveAckMessage);
}
}
}
private void SendReceiveAck(Socket handler, String data)
{
try
{
ProfileProvider.Instance.LogInformationIf(_debug);
// Convert the string data to byte data using ASCII encoding.
byte[] byteData = Encoding.ASCII.GetBytes(data);
handler.Send(byteData);
InstrumentationProvider.Instance.LogInformationIf(_debug, "Message received acknowledgement:" + _receiveAckMessage + " has been sent successfully");
}
catch (Exception ex)
{
InstrumentationProvider.Instance.LogException("SendReceiveAck", ex);
}
}
private void SendConnectedAck(string msg, int clientNumber)
{
ProfileProvider.Instance.LogInformationIf(_debug);
try
{
// Convert the reply to byte array
byte[] byData = System.Text.Encoding.ASCII.GetBytes(msg);
Socket workerSocket = (Socket)workerSocketList[clientNumber - 1];
workerSocket.Send(byData);
InstrumentationProvider.Instance.LogInformationIf(_debug, "Client Connected acknowledgement:" + _clientConnectAckMessage + " has been sent successfully");
}
catch (Exception ex)
{
InstrumentationProvider.Instance.LogException("SendConnectedAck", ex);
throw;
}
}
public void CloseSockets()
{
try
{
ProfileProvider.Instance.LogInformationIf(_debug);
if (m_mainSocket != null)
{
if (m_mainSocket.Connected)
{
m_mainSocket.Shutdown(SocketShutdown.Both);
m_mainSocket.Close();
m_mainSocket = null;
}
}
Socket workerSocket = null;
for (int i = 0; i < workerSocketList.Count; i++)
{
workerSocket = (Socket)workerSocketList[i];
if (workerSocket != null)
{
workerSocket.Shutdown(SocketShutdown.Both);
workerSocket.Close();
workerSocket = null;
}
}
}
catch(Exception ex)
{
InstrumentationProvider.Instance.LogException("CloseSockets",ex);
}
}
protected virtual void OnReceiveComplete(MedDeviceListenerEventArgs e)
{
if (MessageReceived != null)
{
MessageReceived(this, e);
}
}
private int indexOfStartTag(string msg)
{
return msg.IndexOf(header);
}
private int indexOfEndTag(string msg)
{
return msg.IndexOf(footer);
}
private bool isMsgContainsStartTag(string msg)
{
return msg.Contains(header);
}
private bool isMsgContainsEndTag(string msg)
{
return msg.Contains(footer);
}
public delegate void MessageReceiveEventHandler(object sender,MedDeviceListenerEventArgs e);
public class MedDeviceListenerEventArgs : EventArgs,IDisposable
{
private string _receivedData;
public MedDeviceListenerEventArgs(string receivedData)
{
_receivedData = receivedData;
}
public string ReceivedData
{
get
{
return _receivedData;
}
}
public void Dispose()
{ }
}
}
I have read similar posts, tried everything but with no luck. Please help :)
Thanks
-MM

Async chat server buffer issue

can someone please help me out with this... I've been struggling all day.
So I'm trying to learn Async sockets which is something that's been giving me trouble.
The issue is basically the way I'm updating the ListBox with people who have joined the chat room's names:
Basically what I'm doing is having each client send "!!addlist [nickname]" when they join the server.
It's not ideal as it doesn't check for duplicates etc. but now I just want to know why it won't work.
Whenever somebody adds a name they haven't seen before, they will also send "!!addlist [nick]"
In this way, every time someone joins, the lists should be updated for everyone.
The issue seems to be that all the clients start communicating at the same time and it interferes with the buffer.
I've tried using a separate buffer for every client so that's not the issue.
I've tried using lock() but that doesn't seem to be working either.
Essentially what happens is the buffers seem to truncate; where there is data from two different people in the same buffer.
Please just tell me what I'm doing wrong with the buffers or on the client side:
Note that the async socket is using Send instead of BeginSend.
I've tried both methods and they run into the same issue... so it's probably client side?
public partial class Login : Form
{
private ChatWindow cw;
private Socket serverSocket;
private List<Socket> socketList;
private byte[] buffer;
private bool isHost;
private bool isClosing;
public void startListening()
{
try
{
this.isHost = true; //We're hosting this server
cw.callingForm = this; //Give ChatForm the login form (this) [that acts as the server]
cw.Show(); //Show ChatForm
cw.isHost = true; //Tell ChatForm it is the host (for display purposes)
this.Hide(); //And hide the login form
serverSocket.Bind(new IPEndPoint(IPAddress.Any, int.Parse(portBox.Text))); //Bind to our local address
serverSocket.Listen(1); //And start listening
serverSocket.BeginAccept(new AsyncCallback(AcceptCallback), null); //When someone connects, begin the async callback
cw.connectTo("127.0.0.1", int.Parse(portBox.Text), nicknameBox.Text); //And have ChatForm connect to the server
}
catch (Exception) { /*MessageBox.Show("Error:\n\n" + e.ToString());*/ } //Let us know if we ran into any errors
}
public void AcceptCallback(IAsyncResult AR)
{
try
{
Socket s = serverSocket.EndAccept(AR); //When someone connects, accept the new socket
socketList.Add(s); //Add it to our list of clients
s.BeginReceive(buffer, 0, buffer.Length, SocketFlags.None, new AsyncCallback(ReceiveCallback), s); //Begin the async receive method using our buffer
serverSocket.BeginAccept(new AsyncCallback(AcceptCallback), null); //And start accepting new connections
}
catch (Exception) {}
}
public void ReceiveCallback(IAsyncResult AR) //When a message from a client is received
{
try
{
if (isClosing)
return;
Socket s = (Socket)AR.AsyncState; //Get the socket from our IAsyncResult
int received = s.EndReceive(AR); //Read the number of bytes received (*need to add locking code here*)
byte[] dbuf = new byte[received]; //Create a temporary buffer to store just what was received so we don't have extra data
Array.Copy(buffer, dbuf, received); //Copy the received data from our buffer to our temporary buffer
foreach (Socket client in socketList) //For each client that is connected
{
try
{
if (client != (Socket)AR.AsyncState) //If this isn't the same client that just sent a message (*client handles displaying these*)
client.Send(dbuf); //Send the message to the client
}
catch (Exception) { }
} //Start receiving new data again
s.BeginReceive(buffer, 0, buffer.Length, SocketFlags.None, new AsyncCallback(ReceiveCallback), s);
}
catch (Exception) { /*cw.output("\n\nError:\n\n" + e.ToString());*/ }
}
public void SendCallback(IAsyncResult AR)
{
try
{
Socket s = (Socket)AR.AsyncState;
s.EndSend(AR);
}
catch (Exception) { /*cw.output("\n\nError:\n\n" + e.ToString());*/ }
}
Here is the client side:
public void getData()
{
try
{
byte[] buf = new byte[1024];
string message = "";
while(isConnected)
{
Array.Clear(buf, 0, buf.Length);
message = "";
clientSocket.Receive(buf, buf.Length, SocketFlags.None);
message = Encoding.ASCII.GetString(buf);
if (message.StartsWith("!!addlist"))
{
message = message.Replace("!!addlist", "");
string userNick = message.Trim();
if (!namesBox.Items.Contains(userNick))
{
addNick(userNick.Trim());
}
continue;
}
else if (message.StartsWith("!!removelist"))
{
message = message.Replace("!!removelist", "");
string userNick = message.Trim();
removeNick(userNick);
output("Someone left the room: " + userNick);
continue;
}
else if (!namesBox.Items.Contains(message.Substring(0, message.IndexOf(":"))))
{
addNick(message.Substring(0, message.IndexOf(":")).Trim()); //So they at least get added when they send a message
}
output(message);
}
}
catch (Exception)
{
output("\n\nConnection to the server lost.");
isConnected = false;
}
}
Here is my addNick function that seems to fix some things?
public void addNick(string n)
{
if (n.Contains(" ")) //No Spaces... such a headache
return;
if (n.Contains(":"))
return;
bool shouldAdd = true;
n = n.Trim();
for (int x = namesBox.Items.Count - 1; x >= 0; --x)
if (namesBox.Items[x].ToString().Contains(n))
shouldAdd = false;
if (shouldAdd)
{
namesBox.Items.Add(n);
output("Someone new joined the room: " + n);
sendRaw("!!addlist " + nickName);
}
}
I think the issue is that some of the packets are being skipped?
Maybe there's too much code in the client after Receive before it gets called again?
Should I create a separate thread for each message so that receive runs constantly? (Dumb)
Should I have my client use Async receives and sends as well?
I have a feeling that is the answer ^
With all of the checks I do, I managed to clean up the duplicate name issue... but i regularly receive messages with spaces and partial messages from other clients it seems.

Okay so, after messing with this for a long time, I have it relatively stable.
For starters, I added the following state object:
public class StateObject
{
public Socket workSocket = null;
public const int BufferSize = 1024;
public byte[] buffer = new byte[BufferSize];
public StringBuilder sb = new StringBuilder();
public bool newConnection = true;
}
This makes it easy to keep track of each connection and gives each connection its own buffer.
The second thing I did was look for a new line in each message.
I wasn't looking for this in the original code and I believe this was the root of most issues.
I also gave the responsibility of dealing with username management to the server; something that I should have done from the start obviously.
Here is the current server code:
This code is in no way perfect and I'm continuously finding new errors the more I try to break it. I'm going to keep messing with it for awhile but at the moment, it seems to work decently.
public partial class Login : Form
{
private ChatWindow cw;
private Socket serverSocket;
private List<Socket> socketList;
private byte[] buffer;
private bool isHost;
private bool isClosing;
private ListBox usernames;
public Login()
{
InitializeComponent();
}
private void Login_Load(object sender, EventArgs e)
{
ipLabel.Text = getLocalIP();
cw = new ChatWindow();
serverSocket = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
socketList = new List<Socket>();
buffer = new byte[1024];
isClosing = false;
usernames = new ListBox();
}
public string getLocalIP()
{
return Dns.GetHostEntry(Dns.GetHostName()).AddressList.FirstOrDefault(ip => ip.AddressFamily == AddressFamily.InterNetwork).ToString();
}
private void joinButton_Click(object sender, EventArgs e)
{
try
{
int tryPort = 0;
this.isHost = false;
cw.callingForm = this;
if (ipBox.Text == "" || portBox.Text == "" || nicknameBox.Text == "" || !int.TryParse(portBox.Text.ToString(), out tryPort))
{
MessageBox.Show("You must enter an IP Address, Port, and Nickname to connect to a server.", "Missing Info");
return;
}
this.Hide();
cw.Show();
cw.connectTo(ipBox.Text, int.Parse(portBox.Text), nicknameBox.Text);
}
catch(Exception otheree) {
MessageBox.Show("Error:\n\n" + otheree.ToString(),"Error connecting...");
cw.Hide();
this.Show();
}
}
private void hostButton_Click(object sender, EventArgs e)
{
int tryPort = 0;
if (portBox.Text == "" || nicknameBox.Text == "" || !int.TryParse(portBox.Text.ToString(), out tryPort)) {
MessageBox.Show("You must enter a Port and Nickname to host a server.", "Missing Info");
return;
}
startListening();
}
public void startListening()
{
try
{
this.isHost = true; //We're hosting this server
cw.callingForm = this; //Give ChatForm the login form (this) [that acts as the server]
cw.Show(); //Show ChatForm
cw.isHost = true; //Tell ChatForm it is the host (for display purposes)
this.Hide(); //And hide the login form
serverSocket.Bind(new IPEndPoint(IPAddress.Any, int.Parse(portBox.Text))); //Bind to our local address
serverSocket.Listen(1); //And start listening
serverSocket.BeginAccept(new AsyncCallback(AcceptCallback), null); //When someone connects, begin the async callback
cw.connectTo("127.0.0.1", int.Parse(portBox.Text), nicknameBox.Text); //And have ChatForm connect to the server
}
catch (Exception) {}
}
public void AcceptCallback(IAsyncResult AR)
{
try
{
StateObject state = new StateObject();
state.workSocket = serverSocket.EndAccept(AR);
socketList.Add(state.workSocket);
state.workSocket.BeginReceive(state.buffer, 0, StateObject.BufferSize, SocketFlags.None, new AsyncCallback(ReceiveCallback), state);
serverSocket.BeginAccept(new AsyncCallback(AcceptCallback), null);
}
catch (Exception) {}
}
public void ReceiveCallback(IAsyncResult AR)
{
try
{
if (isClosing)
return;
StateObject state = (StateObject)AR.AsyncState;
Socket s = state.workSocket;
String content = "";
int received = s.EndReceive(AR);
if(received > 0)
state.sb.Append(Encoding.ASCII.GetString(state.buffer, 0, received));
content = state.sb.ToString();
if (content.IndexOf(Environment.NewLine) > -1) //If we've received the end of the message
{
if (content.StartsWith("!!addlist") && state.newConnection)
{
state.newConnection = false;
content = content.Replace("!!addlist", "");
string userNick = content.Trim();
if (isHost && userNick.StartsWith("!"))
userNick = userNick.Replace("!", "");
userNick = userNick.Trim();
if (userNick.StartsWith("!") || userNick == string.Empty || usernames.Items.IndexOf(userNick) > -1)
{
//Invalid Username :c get dropped
s.Send(Encoding.ASCII.GetBytes("Invalid Username/In Use - Sorry :("));
s.Shutdown(SocketShutdown.Both);
s.Disconnect(false);
s.Close();
socketList.Remove(s);
return;
}
usernames.Items.Add(userNick);
foreach (string name in usernames.Items)
{
if (name.IndexOf(userNick) < 0)
{
s.Send(Encoding.ASCII.GetBytes("!!addlist " + name + "\r\n"));
Thread.Sleep(10); //such a hack... ugh it annoys me that this works
}
}
foreach (Socket client in socketList)
{
try
{
if (client != s)
client.Send(Encoding.ASCII.GetBytes("!!addlist " + userNick + "\r\n"));
}
catch (Exception) { }
}
}
else if (content.StartsWith("!!removelist") && !state.newConnection)
{
content = content.Replace("!!removelist", "");
string userNick = content.Trim();
usernames.Items.Remove(userNick);
foreach (Socket client in socketList)
{
try
{
if (client != s)
client.Send(Encoding.ASCII.GetBytes("!!removelist " + userNick + "\r\n"));
}
catch (Exception) { }
}
}
else if (state.newConnection) //if they don't give their name and try to send data, just drop.
{
s.Shutdown(SocketShutdown.Both);
s.Disconnect(false);
s.Close();
socketList.Remove(s);
return;
}
else
{
foreach (Socket client in socketList)
{
try
{
if (client != s)
client.Send(System.Text.Encoding.ASCII.GetBytes(content));
}
catch (Exception) { }
}
}
}
Array.Clear(state.buffer, 0, StateObject.BufferSize);
state.sb.Clear();
s.BeginReceive(state.buffer, 0, StateObject.BufferSize, 0, new AsyncCallback(ReceiveCallback), state);
}
catch (Exception) {
socketList.Remove(((StateObject)AR.AsyncState).workSocket);
}
}
public void SendCallback(IAsyncResult AR)
{
try
{
StateObject state = (StateObject)AR.AsyncState;
state.workSocket.EndSend(AR);
}
catch (Exception) {}
}
private void Login_FormClosed(object sender, FormClosedEventArgs e)
{
try
{
this.isClosing = true;
if (this.isHost)
{
foreach (Socket c in socketList)
{
if (c.Connected)
{
c.Close();
}
}
serverSocket.Shutdown(SocketShutdown.Both);
serverSocket.Close();
serverSocket = null;
serverSocket.Dispose();
}
socketList.Clear();
}
catch (Exception) { }
finally
{
Application.Exit();
}
}
}
public class StateObject
{
public Socket workSocket = null;
public const int BufferSize = 1024;
public byte[] buffer = new byte[BufferSize];
public StringBuilder sb = new StringBuilder();
public bool newConnection = true;
}
The client code (work in progress):
public partial class ChatWindow : Form
{
private Socket clientSocket;
private Thread chatThread;
private string ipAddress;
private int port;
private bool isConnected;
private string nickName;
public bool isHost;
public Login callingForm;
private static object conLock = new object();
public ChatWindow()
{
InitializeComponent();
isConnected = false;
isHost = false;
}
public string getIP() {
return Dns.GetHostEntry(Dns.GetHostName()).AddressList.FirstOrDefault(ip => ip.AddressFamily == AddressFamily.InterNetwork).ToString();
}
public void displayError(string err)
{
output(Environment.NewLine + Environment.NewLine + err + Environment.NewLine);
}
public void op(string s)
{
try
{
lock (conLock)
{
chatBox.Text += s;
}
}
catch (Exception) { }
}
public void connectTo(string ip, int p, string n) {
try
{
this.Text = "Trying to connect to " + ip + ":" + p + "...";
this.ipAddress = ip;
this.port = p;
this.nickName = n;
clientSocket = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
if (!isHost)
{
op("Connecting to " + ipAddress + ":" + port + "...");
}
else
{
output("Listening on " + getIP() + ":" + port + "...");
}
clientSocket.Connect(ipAddress, port);
isConnected = true;
if (!isHost)
{
this.Text = "Connected to " + ipAddress + ":" + port + " - Nickname: " + nickName;
output("Connected!");
}
else
{
this.Text = "Hosting on " + getIP() + ":" + port + " - Nickname: " + nickName;
}
chatThread = new Thread(new ThreadStart(getData));
chatThread.Start();
nickName = nickName.Replace(" ", "");
nickName = nickName.Replace(":", "");
if(nickName.StartsWith("!"))
nickName = nickName.Replace("!", "");
namesBox.Items.Add(nickName);
sendRaw("!!addlist " + nickName);
}
catch (ThreadAbortException)
{
//do nothing; probably closing chat window
}
catch (Exception e)
{
if (!isConnected)
{
this.Hide();
callingForm.Show();
clearText();
MessageBox.Show("Error:\n\n" + e.ToString(), "Error connecting to remote host");
}
}
}
public void removeNick(string n)
{
if (namesBox.Items.Count <= 0)
return;
for (int x = namesBox.Items.Count - 1; x >= 0; --x)
if (namesBox.Items[x].ToString().Contains(n))
namesBox.Items.RemoveAt(x);
}
public void clearText()
{
try
{
lock (conLock)
{
chatBox.Text = "";
}
}
catch (Exception) { }
}
public void addNick(string n)
{
if (n.Contains(" ")) //No Spaces... such a headache
return;
if (n.Contains(":"))
return;
bool shouldAdd = true;
n = n.Trim();
for (int x = namesBox.Items.Count - 1; x >= 0; --x)
if (namesBox.Items[x].ToString().Contains(n))
shouldAdd = false;
if (shouldAdd)
{
namesBox.Items.Add(n);
output("Someone new joined the room: " + n);
//sendRaw("!!addlist " + nickName);
}
}
public void addNickNoMessage(string n)
{
if (n.Contains(" ")) //No Spaces... such a headache
return;
if (n.Contains(":"))
return;
bool shouldAdd = true;
n = n.Trim();
for (int x = namesBox.Items.Count - 1; x >= 0; --x)
if (namesBox.Items[x].ToString().Contains(n))
shouldAdd = false;
if (shouldAdd)
{
namesBox.Items.Add(n);
//sendRaw("!!addlist " + nickName);
}
}
public void getData()
{
try
{
byte[] buf = new byte[1024];
string message = "";
while(isConnected)
{
Array.Clear(buf, 0, buf.Length);
message = "";
int gotData = clientSocket.Receive(buf, buf.Length, SocketFlags.None);
if (gotData == 0)
throw new Exception("I swear, this was working before but isn't anymore...");
message = Encoding.ASCII.GetString(buf);
if (message.StartsWith("!!addlist"))
{
message = message.Replace("!!addlist", "");
string userNick = message.Trim();
if(!namesBox.Items.Contains(userNick))
{
addNick(userNick);
}
continue;
}
else if (message.StartsWith("!!removelist"))
{
message = message.Replace("!!removelist", "");
string userNick = message.Trim();
removeNick(userNick);
output("Someone left the room: " + userNick);
continue;
}
output(message);
}
}
catch (Exception)
{
isConnected = false;
output(Environment.NewLine + "Connection to the server lost.");
}
}
public void output(string s)
{
try
{
lock (conLock)
{
chatBox.Text += s + Environment.NewLine;
}
}
catch (Exception) { }
}
private void ChatWindow_FormClosed(object sender, FormClosedEventArgs e)
{
try
{
if(isConnected)
sendRaw("!!removelist " + nickName);
isConnected = false;
clientSocket.Shutdown(SocketShutdown.Receive);
if (chatThread.IsAlive)
chatThread.Abort();
callingForm.Close();
}
catch (Exception) { }
}
private void sendButton_Click(object sender, EventArgs e)
{
if(isConnected)
send(sendBox.Text);
}
private void sendBox_KeyUp(object sender, KeyEventArgs e)
{
if (e.KeyCode == Keys.Enter)
{
if (isConnected)
{
if (sendBox.Text != "")
{
send(sendBox.Text);
sendBox.SelectAll();
e.SuppressKeyPress = true;
e.Handled = true;
}
}
}
}
private void send(string t) {
try
{
byte[] data = System.Text.Encoding.ASCII.GetBytes(nickName + ": " + t + "\r\n");
clientSocket.Send(data);
output(nickName + ": " + t);
}
catch (Exception e)
{
displayError(e.ToString());
}
}
private void sendRaw(string t)
{
try
{
byte[] data = System.Text.Encoding.ASCII.GetBytes(t + "\r\n");
clientSocket.Send(data);
}
catch (Exception e)
{
displayError(e.ToString());
}
}
private void chatBox_TextChanged(object sender, EventArgs e)
{
chatBox.SelectionStart = chatBox.Text.Length;
chatBox.ScrollToCaret();
}
private void sendBox_KeyDown(object sender, KeyEventArgs e)
{
if (e.KeyCode == Keys.Enter)
e.SuppressKeyPress = true;
}
}
To do:
Add invokes, more delegates, do some more QA and find out what breaks it.
Also, I believe there's still the possibility of packet loss due to the client addlist functions being in the read loop. I believe this is why the "crappy hack" using Thread.Sleep(10) in the server callback for name population is an issue.
I think it might be better to either pass the command off to another thread while continuing to read or have the client tell the server it's ready for another name.
Otherwise, there might be some data loss during name updates.
The other thing is that, as was said in the comments above, delegates should be used when updating the UI objects (chatbox and listbox). I wrote the code for these but ultimately removed it because there was no noticeable change and I wanted to keep it simple.
I do still use an object lock when outputting text to the chatbox, but there's no noticeable difference there.
The code should be added as not using delegates is potentially problematic, but I literally caught the chat box in an infinite loop of updates without issue.
I tried breaking it with telnet and was successful so I added a newConnection property to the StateObject to ensure that each client can only send "!!addlist" once.
There are, of course, other ways to abuse the server by creating a client that joins and leaves repeatedly, so ultimately I will probably end up passing the !!removelist handling to the server instead of leaving it up to the client.

Android bluetooth in a service stops sending data after 561K

I wrote a service to send sensor data over bluetooth on android. Although I got no errors my C# client stops getting data after I sent exactly 561K data. At this moment it seems like my android continues to send data but my client doesn't get any. After a while, android also stops sending data. I tried different configurations. My program always stops sending data after "Service->Server". I don't get any errors but it stops sending. Here is android program.
#Override
public synchronized int onStartCommand(Intent intent, int flags, int startId) {
Log.i(EXTRA_MESSAGE,"onStartCommand");
if(isRunning)
Log.e(EXTRA_MESSAGE, "I am already running");
else
{
isRunning = true;
BluetoothDevice selectedDevice = (BluetoothDevice) intent.getParcelableExtra(EXTRA_MESSAGE);
if(selectedDevice == null)
{Log.i(EXTRA_MESSAGE,"null it is "); return -1;}
connect = new ConnectThread(selectedDevice);
connect.start();
mHandler =new Handler(){
#Override
public void handleMessage(Message msg) {
super.handleMessage(msg);
switch(msg.what){
case SUCCESS_CONNECT:
connected = new ConnectedThread((BluetoothSocket) msg.obj);
Toast.makeText(getApplicationContext(), "Connected", 0).show();
//connected.write(("Connected").getBytes());
Log.i(EXTRA_MESSAGE, "we are connected");
isConnected = true;
break;
case MESSAGE_READ:
Toast.makeText(getApplicationContext(), ((byte[]) msg.obj).toString(), 0).show();
break;
}
}
};
mSensor = (SensorManager) getSystemService(SENSOR_SERVICE);
sSensor = mSensor.getDefaultSensor(Sensor.TYPE_ORIENTATION);
mSensor.registerListener(this, sSensor,SensorManager.SENSOR_DELAY_NORMAL);
// sSensor = mSensor.getDefaultSensor(Sensor.TYPE_ACCELEROMETER);
// mSensor.registerListener(this, sSensor,SensorManager.SENSOR_DELAY_NORMAL);
sSensor = mSensor.getDefaultSensor(Sensor.TYPE_GYROSCOPE);
mSensor.registerListener(this, sSensor,SensorManager.SENSOR_DELAY_NORMAL);
}
return super.onStartCommand(intent, flags, startId);
}
#Override
#Override
public void onSensorChanged(SensorEvent event) {
Log.i(EXTRA_MESSAGE, "Sensor data arrived");
if(isConnected )
{
String toSend = Integer.toString(event.sensor.getType())+ ":" + Long.toString(event.timestamp)+ ":";
for(float f : event.values){
toSend = toSend + Float.toString(f)+":";
}
//
connected.write(toSend.getBytes());
}
}
private class ConnectThread extends Thread {
private final BluetoothSocket mmSocket;
private final BluetoothDevice mmDevice;
public ConnectThread(BluetoothDevice device) {
// Use a temporary object that is later assigned to mmSocket,
// because mmSocket is final
BluetoothSocket tmp = null;
mmDevice = device;
// Get a BluetoothSocket to connect with the given BluetoothDevice
try {
// MY_UUID is the app's UUID string, also used by the server code
tmp = device.createRfcommSocketToServiceRecord(MY_UUID);
Log.i(EXTRA_MESSAGE,"connectThread started successfully");
} catch (IOException e) { }
mmSocket = tmp;
}
public void run() {
// Cancel discovery because it will slow down the connection
try {
// Connect the device through the socket. This will block
// until it succeeds or throws an exception
mmSocket.connect();
Log.i(EXTRA_MESSAGE,"connectThread connect successfully");
} catch (IOException connectException) {
// Unable to connect; close the socket and get out
Log.i(EXTRA_MESSAGE,"connectThread connect exception");
try {
mmSocket.close();
} catch (IOException closeException) { }
}
// Do work to manage the connection (in a separate thread)
mHandler.obtainMessage(SUCCESS_CONNECT, mmSocket).sendToTarget();
}
/** Will cancel an in-progress connection, and close the socket */
public void cancel() {
try {
mmSocket.close();
} catch (IOException e) { }
}
}
private class ConnectedThread extends Thread {
private final BluetoothSocket mmSocket;
private final InputStream mmInStream;
private final OutputStream mmOutStream;
public boolean shouldContinue = true;
int nBytes =0;
public ConnectedThread(BluetoothSocket socket) {
mmSocket = socket;
InputStream tmpIn = null;
OutputStream tmpOut = null;
// Get the input and output streams, using temp objects because
// member streams are final
try {
tmpIn = socket.getInputStream();
tmpOut = socket.getOutputStream();
Log.i(EXTRA_MESSAGE,"connectedThread sockets");
} catch (IOException e) { }
mmInStream = tmpIn;
mmOutStream = tmpOut;
}
public void run() {
byte[] buffer; // buffer store for the stream
int bytes; // bytes returned from read()
// Keep listening to the InputStream until an exception occurs
while(shouldContinue) {
try {
// Read from the InputStream
buffer = new byte[1024];
bytes = mmInStream.read(buffer);
// Send the obtained bytes to the UI activity
Log.e(EXTRA_MESSAGE, " We read");
mHandler.obtainMessage(MESSAGE_READ, bytes, -1, buffer)
.sendToTarget();
} catch (IOException e) {
break;
}
}
}
/* Call this from the main activity to send data to the remote device */
public void write(byte[] bytes) {
try {
Log.i(EXTRA_MESSAGE,"Service->Server");
mmOutStream.write(bytes);
nBytes += bytes.length;
Log.i(EXTRA_MESSAGE,"ok" + String.valueOf(nBytes ));
} catch (IOException e) {
Log.i(EXTRA_MESSAGE,"exception");
}
}
/* Call this from the main activity to shutdown the connection */
public void cancel() {
try {
shouldContinue = false;
mmSocket.close();
} catch (IOException e) { }
}
}
Also my c# thread is as follows
public void ServerConnectThread()
{
serverStarted = true;
int counter = 0;
updateUI("Server started, waiting for clients");
BluetoothListener blueListener = new BluetoothListener(mUUID);
blueListener.Start();
BluetoothClient conn = blueListener.AcceptBluetoothClient();
updateUI("Client has connected");
Stream mStream = conn.GetStream();
while (true)
{
try
{
//handle server connection
byte[] received = new byte[1024];
mStream.Read(received, 0, received.Length);
counter += Encoding.ASCII.GetString(received).Length;
String[] fields = Encoding.ASCII.GetString(received).Split(':');
double[] data = new double[3];
for (int i = 2; i < 5; i++) data[i-2] = double.Parse(fields[i]);
//mSource.notifyObserver(Int16.Parse(fields[0]), data);
updateUI(counter.ToString() + " "+ fields[2]+ ":" + fields[3] + ":" + fields[4]);
byte[] sent = Encoding.ASCII.GetBytes("Hello World");
mStream.Write(sent, 0, sent.Length);
}
catch (IOException exception)`enter code here`
{
updateUI("Client has disconnected!!!!");
}
}
}
One final thing is I've found thousands of 561K android program which sounded a little interesting.

Ok I found my own problem. Basically I m sending a reply from my client when I got the sensor data and It is not handled by android app.

Sockets: Send strings from Java to C#?

I need to send string messages from Java program to C# program in real time.
There are many examples in the Internet but U can't find anything good for my purpose that is (probably) Java client (sockets code) and c# server (sockets code).
Thank you.

Ok i already did this in one of my projects so here it is:
disclaimer: some of the code (only a little bit actually) is based on nakov chat server.
also note that i decode and encode all the messages sent and recived in UTF-8.
Java Code:
Class: Server
import java.net.*;
import java.io.*;
import javax.swing.*;
public class Server
{
private static void createAndShowGUI() {
//Create and set up the window
}
public static final int LISTENING_PORT = 2002;
public static void main(String[] args)
{
// Open server socket for listening
ServerSocket serverSocket = null;
try
{
serverSocket = new ServerSocket(LISTENING_PORT);
javax.swing.SwingUtilities.invokeLater(new Runnable() {
public void run() {
createAndShowGUI();
}
});
//System.out.println("Server started on port " + LISTENING_PORT);
}
catch (IOException se)
{
System.err.println("Can not start listening on port " + LISTENING_PORT);
se.printStackTrace();
System.exit(-1);
}
// Start ServerDispatcher thread
ServerDispatcher serverDispatcher = new ServerDispatcher();
// Accept and handle client connections
while (true)
{
try
{
Socket socket = serverSocket.accept();
ClientInfo clientInfo = new ClientInfo();
clientInfo.mSocket = socket;
ClientListener clientListener =
new ClientListener(clientInfo, serverDispatcher);
ClientSender clientSender =
new ClientSender(clientInfo, serverDispatcher);
clientInfo.mClientListener = clientListener;
clientInfo.mClientSender = clientSender;
clientListener.start();
clientSender.start();
serverDispatcher.addClient(clientInfo);
}
catch (IOException ioe)
{
ioe.printStackTrace();
}
}
}
}
Class Message Dispatcher:
import java.io.UnsupportedEncodingException;
import java.net.*;
import java.util.*;
public class ServerDispatcher
{
private Vector mMessageQueue = new Vector();
private Vector<ClientInfo> mClients = new Vector<ClientInfo>();
public synchronized void addClient(ClientInfo aClientInfo) {
mClients.add(aClientInfo);
}
public synchronized void deleteClient(ClientInfo aClientInfo) {
int clientIndex = mClients.indexOf(aClientInfo);
if (clientIndex != -1)
mClients.removeElementAt(clientIndex);
}
private synchronized void sendMessageToAllClients(String aMessage)
{
for (int i = 0; i < mClients.size(); i++) {
ClientInfo infy = (ClientInfo) mClients.get(i);
infy.mClientSender.sendMessage(aMessage);
}
}
public void sendMessage(ClientInfo aClientInfo, String aMessage) {
aClientInfo.mClientSender.sendMessage(aMessage);
}
}
Class: ClientInfo
/**
*
* ClientInfo class contains information about a client, connected to the server.
*/
import java.awt.List;
import java.net.Socket;
import java.util.ArrayList;
import java.util.Vector;
public class ClientInfo
{
public int userID=-1;
public Socket mSocket = null;
public ClientListener mClientListener = null;
public ClientSender mClientSender = null;
}
Class ClientListner:
/**
* ClientListener class is purposed to listen for client messages and
* to forward them to ServerDispatcher.
*/
import java.io.*;
import java.net.*;
public class ClientListener extends Thread {
private ServerDispatcher mServerDispatcher;
private ClientInfo mClientInfo;
private BufferedReader mIn;
private String message;
private String decoded = null;
public ClientListener(ClientInfo aClientInfo,
ServerDispatcher aServerDispatcher) throws IOException {
mClientInfo = aClientInfo;
mServerDispatcher = aServerDispatcher;
Socket socket = aClientInfo.mSocket;
mIn = new BufferedReader(new InputStreamReader(socket.getInputStream()));
}
/**
* Until interrupted, reads messages from the client socket, forwards them
* to the server dispatcher and notifies the server dispatcher.
*/
public void run() {
message = "";
while (!isInterrupted()) {
try {
message = mIn.readLine();
if (message == null)
break;
try {
decoded = URLDecoder.decode(message, "UTF-8");
} catch (UnsupportedEncodingException e)
e.printStackTrace();
}
mServerDispatcher.sendMessage(mClientInfo, decoded);
}
catch (IOException e) {
break;
}
}
// Communication is broken. Interrupt both listener and sender threads
mClientInfo.mClientSender.interrupt();
mServerDispatcher.deleteClient(mClientInfo);
}
}
Class:ClientSender
/**
* Sends messages to the client. Messages are stored in a message queue. When
* the queue is empty, ClientSender falls in sleep until a new message is
* arrived in the queue. When the queue is not empty, ClientSender sends the
* messages from the queue to the client socket.
*/
import java.io.*;
import java.net.*;
import java.util.*;
public class ClientSender extends Thread
{
private Vector mMessageQueue = new Vector();
private ServerDispatcher mServerDispatcher;
private ClientInfo mClientInfo;
private PrintWriter mOut;
public ClientSender(ClientInfo aClientInfo, ServerDispatcher aServerDispatcher)
throws IOException
{
mClientInfo = aClientInfo;
mServerDispatcher = aServerDispatcher;
Socket socket = aClientInfo.mSocket;
mOut = new PrintWriter(new OutputStreamWriter(socket.getOutputStream()));
}
/**
* Adds given message to the message queue and notifies this thread
* (actually getNextMessageFromQueue method) that a message is arrived.
* sendMessage is called by other threads (ServeDispatcher).
*/
public synchronized void sendMessage(String aMessage)
{
mMessageQueue.add(aMessage);
notify();
}
/**
* #return and deletes the next message from the message queue. If the queue
* is empty, falls in sleep until notified for message arrival by sendMessage
* method.
*/
private synchronized String getNextMessageFromQueue() throws InterruptedException
{
while (mMessageQueue.size()==0)
wait();
String message = (String) mMessageQueue.get(0);
mMessageQueue.removeElementAt(0);
return message;
}
/**
* Sends given message to the client's socket.
*/
private void sendMessageToClient(String aMessage)
{
String encoded;
try {
encoded = URLEncoder.encode(aMessage,"UTF-8");
mOut.println(encoded);
mOut.flush();
} catch (UnsupportedEncodingException e) {
e.printStackTrace();
}
}
/**
* Until interrupted, reads messages from the message queue
* and sends them to the client's socket.
*/
public void run()
{
try {
while (!isInterrupted()) {
String message = getNextMessageFromQueue();
sendMessageToClient(message);
}
} catch (Exception e) {
// Commuication problem
break;
}
// Communication is broken. Interrupt both listener and sender threads
mClientInfo.mClientListener.interrupt();
mServerDispatcher.deleteClient(mClientInfo);
}
}
Ok this is the java code,now to the c# code
c# Code:
Varibales used:
private StreamWriter swSender;
private StreamReader srReceiver;
private TcpClient tcpServer;
private Thread thrMessaging;
private IPAddress ipAddr;
private bool Connected;
Function: Intelize connection:
private void InitializeConnection()
{
// Parse the IP address
string ipAdress = "XXX.XXX.XXX.XXX";
ipAddr = IPAddress.Parse(ipAdress);
// Start a new TCP connections to the chat server
tcpServer = new TcpClient();
try
{
tcpServer.Connect(ipAddr, 2002);
swSender = new StreamWriter(tcpServer.GetStream());
// Start the thread for receiving messages and further communication
thrMessaging = new Thread(new ThreadStart(ReceiveMessages));
thrMessaging.Start();
Connected=true;
}
catch (Exception e2)
{
MessageBox.Show(e2.ToString());
}
}
}
Function: ReciveMessages
private void ReceiveMessages()
{
// Receive the response from the server
srReceiver = new StreamReader(tcpServer.GetStream());
while (Connected)
{
String con = srReceiver.ReadLine();
string StringMessage = HttpUtility.UrlDecode(con, System.Text.Encoding.UTF8);
processMessage(StringMessage);
}
}
Function: proceesMessage:
private void processMessage(String p)
{
// do something with the message
}
Function sendMessage:
private void SendMessage(String p)
{
if (p != "")
{
p = HttpUtility.UrlEncode(p, System.Text.Encoding.UTF8);
swSender.WriteLine(p);
swSender.Flush();
}
}
thats it thats all you need to have communication between java server and c# client. if you have any questions dont hesitate to post them here.

Choose a protocol for encoding/sending your strings. For instance:
<length of string (4 bytes)><string data (length bytes)>
Write some Java code to send a string that follows whatever protocol you chose in #1. So using the example above, you could do something like:
public static void writeString(String string, OutputStream out) throws IOEXception {
if (string == null || "".equals(string)) {
//nothing to do
return;
}
int length = string.length();
//synchronize so that two threads don't try to write to the same stream at the same time
synchronized(out) {
out.write((length >> 24) & 0xFF);
out.write((length >> 16) & 0xFF);
out.write((length >> 8) & 0xFF);
out.write(length & 0xFF);
out.write(string.getBytes());
out.flush();
}
}
Write some equivalent code in C# to decode the strings that are being sent. It will look a lot like your Java code, except with reads instead of writes.

I think I've found a good, working solution. Using UDP sockets:
Java code
public void runJavaSocket() {
System.out.println("Java Sockets Program has started."); int i=0;
try {
DatagramSocket socket = new DatagramSocket();
System.out.println("Sending the udp socket...");
// Send the Message "HI"
socket.send(toDatagram("HI",InetAddress.getByName("127.0.0.1"),3800));
while (true) {
System.out.println("Sending hi " + i);
Thread.currentThread();
Thread.sleep(1000);
socket.send(toDatagram("HI " +
String.valueOf(i),InetAddress.getByName("127.0.0.1"),3800));
i++;
}
} catch (Exception e) {
e.printStackTrace();
}
}
public DatagramPacket toDatagram(
String s, InetAddress destIA, int destPort) {
// Deprecated in Java 1.1, but it works:
byte[] buf = new byte[s.length() + 1];
s.getBytes(0, s.length(), buf, 0);
// The correct Java 1.1 approach, but it's
// Broken (it truncates the String):
// byte[] buf = s.getBytes();
return new DatagramPacket(buf, buf.length, destIA, destPort);
}
C# code
string returnData;
byte[] receiveBytes;
//ConsoleKeyInfo cki = new ConsoleKeyInfo();
using (UdpClient udpClient =
new UdpClient(new IPEndPoint(IPAddress.Parse("127.0.0.1"), 3800)))
{
IPEndPoint remoteIpEndPoint =
new IPEndPoint(IPAddress.Parse("127.0.0.1"), 3800);
while (true)
{
receiveBytes = udpClient.Receive(ref remoteIpEndPoint);
returnData = Encoding.ASCII.GetString(receiveBytes);
Console.WriteLine(returnData);
}
}

I would just use SOAP protocol. You can use WCF on the C# side and JMS (Java messging) on the Java side. Both these technologies are built on SOAP so they can read each other's messages. They both use WSDL.